Control for variable radio tuning units



@636. 3, 1929. HEDSTRQM 1,738,369

CONTROL FOR VARIABLE RADIO TUNING UNITS Filed March 12, 1925 gnvewfoz G VT Ziedafram,

Patented Dec. 3, 1929 PATENT OFFICE GUSTAV V. HEDSTROM, 0F KENOSHA, WISCONSIN CONTROL FOR VARIABLE RADIO TUNING UNITS Application filed March 12, 1925. Serial No. 15,084.

This invention relates to'radio receiving apparatus, and more particularly to the variable condensers and variable inductance devices for such apparatus.

.5' I The invention has for one of its objects the provision of novel and simple means through the medium of which the movable units of a condenser or inductance device may 'besimultaneously adjusted or rotated from a single or master control.

A further object of the invention is the provision of novel and simple means through the medium of which the movable units of any number of condensers or inductance de vices may be simultaneously adjusted or rotated from a single or master control. i

A still further object of the invention is the provision of means of the character stated which shall be adapted to permit the variable units of condensers or inductance devices to be uniformly and smoothly adjusted or rotated, and which shall be adapted to permit the variable units of such devices to be adjusted or rotated with the minimum of 2 play or lost motion.

The foregoing and other objects are attained by the construction, combination and arrangement of parts hereinafter fully described and claimed, and illustrated in the an accompanying drawing, wherein:

Figure 1 is-a top plan view of afragmentary portion of a radio receiving set, illustrating the application of the invention to variable plate condensers.

Figure 2 is a sectional view taken on the plane indicated by the line 22 of Figure 1, and

Figure 3 is an elevational view illustrating the application of the invention to a plate condenser having a plurality of adjustable or movable units.

Corresponding and like parts are referred to in the following descriptiornand designated in the several views of the accompanying drawing, by similar reference characters.

In the drawing 1 and I designate variable plate condensers each of which comprises a movable unit of plates 3, and a movable unit of plates 4', the unit 3 being carried by a shaft 5 and the unit 4 by a shaft 6. The shafts 5 and 6 are journale'd in a panel 7 and in a strip 8 secured to the panel by bolts 9. Only one of the shafts 5 and 6 project through the panel 7, and such shaft is provided with a master control preferably in the form of a knob 10.

Levers 11 which may be formed integrally with the shafts 5 and 6 or made separately and secured thereto by set screws 12, extend in a common direction from the shafts and are connected by a link 13. The levers 11 and link 13 establish such a connection between the movable units 3 and 4 of the condensers 1 and 1 that when the knob 10 is turned said units are simultaneously turned to an equal degree. The link 13 is connected to the free ends of the levers 11 by pivots 14.

In Figure 3 the invention is shown applied to a variable plate condenser having a single set of plate units designated 3 and 4* respectively. The unit 3 is mounted upon a shaft 5 and the unit Ron a shaft 6. In this figure the levers are designated 11 and the a links 13, and the master control 10 could be secured to either the shaft 5 or 6.

Although the invention is shown only in connection with variable plate condensers, the manner in which it may be used in connection with variable inductance devices should be readily apparent to those skilled in the art,- and therefore a disclosure of this particular application of the invention is deemed unnecessary.

From the foregoing description, taken in connection with the accompanying drawing, it should be apparent that it is very simple, that it may be readily applied to any of the many well known forms of variableplate condensers and variable inductance devices, and that it may be manufactured and sold at a comparatively low cost.

What I claim as my invention is In combination, a plurality of condensers each embodying a pair of relatively spaced shafts and units of plates secured to the shafts, the units of plates of each condenser being adjustable relatively from and into a position between the shafts, levers connected to the shafts and extending in a common direction therefrom, a link connected to the levers, and a master control connected to one of the shafts, said levers and link connecting the plate units of the respective condensers for relative adjustment through equal angles.

In testimony whereof I aflix my signature.

GUSTAV V. HEDSTROM. 

